This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
Before the trials of the past winter are forgotten in the warmth and sunshine that may be expected soon, it may not be out of place to make one or two allusions to certain matters in forcing operations, which will have been but too lucidly demonstrated of late, unless where the most complete and perfect appliances for forcing have been at command.
Not since the memorable winters of 1860-61, or 1866-67, have we had anything at all approaching the severity of the past winter, either in the intensity of the cold or the duration of the storm - to say nothing of the grim fogs, which were so dense in our district as to render it a difficulty at times to discern the difference between day and night. With regard to forcing-houses, and heating apparatus in particular, those who depended or relied upon having such a winter as we have been accustomed to since 1870 must have discovered how unwise it is not to have their knapsack, like the famous Scotch general, "always in marching order." For ourselves, we discovered, just about the middle of the storm, a leakage in connection with one boiler which heated three small forcing-houses, one of which had been a recent addition. The boiler was not of sufficient capacity before the addition was made, but upon being reset an improvement was effected; and it was only upon its trial for another winter, in order to test its power, - not calculating, of course, upon the severe winter that was coming on.
In another case, where there were two boilers - one of which gave way at the rivets during the early part of the summer, and was not replaced, because its companion was a powerful new boiler, and was calculated to do the work of both, - this was also a cause of interminable watching and dreary suspense, as it was found that the increased pressure upon the boiler was more than it was safely capable of doing; and a breakdown would have been a misfortune, in the most charitable way it can be looked at. Doubtless there have been many similar cases elsewhere, where the opportunity should not be neglected of laying the matter seriously before employers, and explaining the consequences of a breakdown, in order that doubts as to the economy and necessity of introducing such additions to existing arrangements as are required should be removed.
Wherever there is anything like an important charge in forcing, there can be no plea advanced in favour of that economy which assumes to be a saving, to face a winter like the past one either with deficient boiler-power or insufficient heating-surface. The former is dangerous, and the reverse of economical; whilst the latter is neither economical, nor does it afford healthy conditions under which the tender leaves can progress with satisfaction. Another great defect, and one that is most noticeable in the vicinity of large towns, is that detached system of grouping houses, without any notion of condensing, as it were, labour, or of affording means of minimising such material as may be required for the working of them.
Now it would be a matter of comparative simplicity, in the formation of new places, for employers to take the advice, in the first place, of some practical and competent authority, who, whether he had to build one house or six, would not only work upon approved principles, but would also anticipate additions by which heating power could still be supplied from one given point, and would always calculate upon leaving room for further extension, as the situation and other circumstances would suggest.
Houses that stand high, and are exposed to searching winds, should always have an additional pipe; and no block of forcing-houses should be heated by less than two boilers, which should work either conjointly or independently of each other.
We have had sharp experience lately; and we would again repeat that such an opportunity should not be overlooked, where it has been found necessary, of laying before employers matters of such vital interest to all concerned; because, from any point of view, those who have been best equipped with boilers and pipes have saved most in labour and fuel. Practitioner.